SuFac
SuFac, or super factorial, is superfunction of Factorial constructed with regular iteration at the fixed point $L\!=\!2$ with additional condition $\mathrm{suFac}(0)\!=\!3$.
Explicit plot $y\!=\!\mathrm{SuFac}(x)$ is shown in figure at right with blue curve in comparison with graphic of factorial, $y\!=\!\mathrm{Factorial}(x)$, shown with red line.
The numerical implementation in C++ of SuFac is loaded as sufac.cin.
References
http://www.springerlink.com/content/qt31671237421111/fulltext.pdf?page=1
http://www.ils.uec.ac.jp/~dima/PAPERS/2010superfae.pdf
http://mizugadro.mydns.jp/PAPERS/2010superfae.pdf
D.Kouznetsov, H.Trappmann. Superfunctions and square root of factorial. Moscow University Physics Bulletin, 2010, v.65, No.1, p.6-12.
http://mizugadro.mydns.jp/PAPERS/2010superfar.pdf Д,Кузнецов, Г.Траппманн. Суперфункции и корень их факториала. Вестник Московского Университета, серия 3, 2010, стр.8-14)